Once you start going back in time and preventing tragedies, where does it stop? After we save the ancients, why don't we go back in time and save Minfilia, and Loiusiox, and every other npc we have ever lost. The cast can just start ballooning with alternative timeline versions of every character.

How could any tragedy ever have any impact if we could just go hop in the crystal tower and reverse it? I think it's better if time travel has some limitations on how you can influence past events. The 8UC stuff only works narratively because the WoL was so far removed from it.